The invention generally relates to a modular assembly for portable radio receivers having a subassembly allowing changes in the character of radio output and the main receiver assembly having means for attaching and locking the subassembly to the main receiver housing. More particularly, the invention relates to an assembly for a pager having means for quickly and easily engaging and disengaging various output control device subassemblies which interface with a generic radio frequency receiver enclosed in a main pager housing.
Many different annunication means are known to alert a pager user when a transmitted signal is received by the pager. Audio tone and voice output devices have been the most common, but there are also audiovisual display output devices and vibration output devices. In the past, each different type of alerting output has required a separate pager unit with individual assembly and component parts. This has been true even though each different type pager shares common component subsystems. In particular, the receiver portion of the pager's electronics is virtually identical in each different type pager unit. The decoder circuitry and alert circuitry are those portions of the pager which differ for pagers with different output devices. In the past even though a major portion of the pager device was common with other pagers having different output features, each pager had its own separate assembly. These separate assembly lines for devices with major common portions result in an unnecessary increase in manufacturing costs and duplication of inventory.
Recently attempts have been made to develop pagers whose main housing is generic to all the different output type paging devices. The object of this is to have the capability of changing a given pager from one output type to another while maintaining the same distinctive trade dress for the different pager types. These recent attempts have utilized a generic housing but have required a complete replacement of the internal component assembly. This meant only the housing shell was carried over from one system to another. Such a replacement ability allowed ease in manufacturing since only one main housing die was required for all the different pagers, but it offered little benefit to the user since to switch from one system to another required buying virtually a whole new pager while reusing only the comparatively inexpensive housing shell. There is a need for a modular construction for a pager which would have the flexibility to allow changes in pager output characteristics without a wholesale replacement of the pager internal components common to all types of pagers.
Problems have also existed in the assembly process of prior art pagers. Usually a pager is housed in a six sided box. For aesthetic reasons, it is desirable for the pager housing to have a minimal number of exposed support screws. A desire to simplify the pager assembly process combined with a desire for pleasing aesthetics, has commonly resulted in the use of only one side of the pager housing as an access opening to pager components. Usually all the internal components are mounted and arranged with respect to one another on a single component board so that they may slide as a unit into position within the housing cavity during assembly. Persuant to the desire to simplify the assembly process, often the component board includes all externally accessable components, such as switches. The resulting assembly process is simply and easy but it is at the expense of a certain flexibility in the mounting of the externally available displays, switches and buttons. Push buttons (usually dome switches) or slide switches, to be functional, must protrude from the housing through openings. In an assembly arrangement where the pager internal components are on a single board that slides into place through a single side opening of the pager housing, the housing sides adjacent to the opened side are necessarily parallel to the line of travel of the internal components as the component board slides into place and are therefore practically excluded from having switches protruding from their surface plane. To include switches mounted on these adjacent walls would require some means of detenting their protruding portions as they slide into the housing cavity. Provisions could be made to accomplish this but it would cut away from the basic assembly objective of simplicity. In light of this, there is a need for a modular assembly that is as simple as the modular assemblies of the prior art yet allows the pleasing aesthetics of mounting switches on two adjacent housing sides.
Therefore it is an object of this invention to create a modular pager housing allowing easy assembly and a greater flexibility in the placement of displays, buttons and switches on the pager housing.
It is a further object of the invention to provide interchangable subassemblies for a pager which allows a generic radio receiver housing and circuitry to be complemented by a decoder and user alert subassembly circuit housed by a subassembly cover which is easily mechanically and electrically mounted onto the main housing of the generic receiver portion of the pager while simultaneously maintaining a pleasing aesthetic appearance.